EOS R5 Mark II - Full Card Error

[natureshots]

I use Lexar 512GB professional silver SE CFexpress Type B memory card in my R5 MII. I randomly encountered card full error, only with the CFE card so far, even though the card was just formatted or the camera had been used hours before. I tried power off and on, re=inserting the battery and re-inserting the card but nothing worked. The camera worked fine after replacing the CFE with an SD card. I thought it was a card; so it was returned for a replacement of the same type. I've used the second CFE card and haven't encountered the issue again until on a recent camping trip. So it seems like an issue with the camera instead of the card.

I do vaguely remember only encountering this card full issue in about freezing environments. So, it seems like the R5 II may have an issue with operating in cold environments with the CFE cards? Is this issue known? I tried searching but no relevant results.

[jmrozew1]

Exact same issue. Exact same card. I believe this is temperature-dependent; putting the card in the freezer for a few minutes causes this to happen, as does the weather being cool. The issue isn't present when I do the same with a SanDisk branded card. In other words, this is probably a complicate combination of card error for a specific brand, running in to some software or firmware failsafes that the camera has built-in when it initializes a card. I contacted Lexar about this issue, asking for a card refund or replacement (hoping for a refund, to be honest, haha).

[p4pictures]

Are you shooting stills or movies? 

If movies, it is possible that the camera has reached clip number 999. This is the limit for movie clips on a card. 

https://cam.start.canon/en/C017/manual/html/UG-07_Set-up_0060.html